Combating fungi with 2-methylene-3-substituted-4,5-bis-trifluoro-methyl imino-thiazolidines

ABSTRACT

2-Methylene-3-substituted-4,5-bis-trifluoromethylimino-thiazoldines of the formula ##STR1## in which R 1  represents optionally substituted alkyl, optionally substituted alkenyl, optionally substituted alkynyl, optionally substituted cycloalkyl, optionally substituted aryl, aralkyl, it being possible for the last-mentioned group to be substituted on the alkyl radical, or an amino group --NR 4  R 5 , wherein 
     R 4  and R 5  may be identical or different, each represent optionally substituted alkyl, or R 4  and R 5  together with the connecting nitrogen atom and optionally one or more further heteroatoms, form a 4-membered to 12-membered heterocyclic ring, 
     R 2  represents cyano, alkoxycarbonyl, acyl, alkylsulphonyl or arylspulphonyl, the four last-mentioned groups being optionally substituted, or represents an amide or thioamide group, comprising the radical CO--NR 6  R 7  or CS--NR 6  R 7 , wherein 
     R 6  represents hydrogen or alkyl and 
     R 7  represents alkyl, cycloalkyl or optionally substituted phenyl, or 
     R 2  and R 3 , together with the connecting carbon atom, represent an α-cycloalkanone ring system with 5 to 7 carbon atoms, which can be optionally substituted, 
     which possess fungicidal properties.

The present invention relates to and has for its objects the provisionof particular new2-methylene-3-substituted-4,5-bis-trifluoromethylimino-thiazolidineswhich possess fungicidal properties, active compositions in the form ofmixtures of such compounds with solid and liquid dispersible carriervehicles, and methods for producing such compounds and for using suchcompounds in a new way especially for combating pests, e.g. fungi, withother and further objects becoming apparent from a study of the withinspecification and accompanying examples.

As is known, zinc ethylene-bis-dithiocarbamate is used to a large extentfor combating fungi which are harmful to plants (see Phytopathology 33,1113 (1943)), but the action of this standard preparation is not alwayscompletely satisfactory. 4,5-Bis-trifluoromethyliminothiazolidines,which are likewise known, also have a good fungicidal activity (see, inthis context, U.S. Pat. No. 3,895,020), but in this case also the actiondisplayed is not always completely satisfactory when low amounts areused.

The present invention now provides, as new compounds, thetrifluoromethylimino-thiazolidine derivatives of the general formula##STR2## in which R¹ represents optionally substituted alkyl, optionallysubstituted alkenyl, optionally substituted alkynyl, optionallysubstituted cycloalkyl, optionally substituted aryl, aralkyl, it beingpossible for the last-mentioned group to be substituted on the arylradical, or an amino group --NR⁴ R⁵, wherein

R⁴ and R⁵, which may be identical or different, each representoptionally substituted alkyl, or R⁴ and R⁵, together with the connectingnitrogen atom and optionally one or more further hetero-atoms, such asoxygen, sulphur or nitrogen, form a 4-membered to 12-memberedheterocyclic ring,

R² represents hydrogen, cyano, alkoxycarbonyl or acyl and

R³ represents cyano, alkoxycarbonyl, acyl, alkylsulphonyl orarylsulphonyl, the four last-mentioned groups being optionallysubstituted, or represents an amide or thioamide group, comprising theradical CO--NR⁶ R⁷ or CS--NR⁶ R⁷, wherein

R⁶ represents hydrogen or alkyl and

R⁷ represents alkyl, cycloalkyl or optionally substituted phenyl, or

R² and R³, together with the connecting carbon atom, represent anα-cycloalkanone ring system with 5 to 7 carbon atoms, which can beoptionally substituted.

Preferably, R¹ represents a straight-chain or branched alkyl, alkenyl oralkynyl radical with up to 6 (especially up to 4) carbon atoms, whichradical can be substituted by cyano or an alkoxy or alkylmercapto groupwith in either case up to 3 carbon atoms, or represents cycloalkyl with5 to 6 carbon atoms, which is optionally substituted by alkyl with 1 to3 carbon atoms, or represents aryl with up to 10 carbon atoms or aralkylwith up to 10 carbon atoms in the aryl part and 1 or 2 carbon atoms inthe alkyl part, the aryl radicals mentioned being optionally substitutedby halogen, cyano, nitro or alkyl, alkoxy or alkylmercapto with in eachcase up to 3 carbon atoms, or represents an amino group --NR⁴ R⁵,wherein R⁴ and R⁵, which may be identical or different, each representstraight-chain or branched alkyl with 1 to 12 (especially 1 to 4) carbonatoms, or R⁴ and R⁵ together with the connecting nitrogen atom andoptionally one or more further heteroatoms selected from oxygen, sulphurand nitrogen, form a heterocyclic ring with 5 to 7 ring atoms;

R² represents hydrogen, cyano, alkoxycarbonyl with up to 4 carbon atomsin the alkyl part or an acyl group with a total of up to 10 (especiallyup to 4) carbon atoms; and

R³ represents cyano or alkoxycarbonyl with up to 4 carbon atoms in thealkyl part and which can be optionally substituted by an alkoxy oralkylmercapto group with up to 3 carbon atoms, or represents an acylgroup with a total of up to 10 carbon atoms (especially up to 6 carbonatoms), alkylsulphonyl with up to 6 carbon atoms or arylsulphonyl withup to 10 carbon atoms in the aryl part, which aryl part is optionallysubstituted by alkyl with up to 3 carbon atoms and/or nitro and/orhalogen, or represents an amide or thioamide group comprising theradical CO--NR⁶ R⁷ or CS--NR⁶ R⁷, in which R⁶ represents hydrogen oralkyl with up to 4 carbon atoms and R⁷ represents alkyl with up to 6carbon atoms, cycloalkyl with 5 or 6 carbon atoms or phenyl, whichphenyl can be substituted by halogen, nitro or alkyl, alkoxy oralkylmercapto with in each case up to 4 carbon atoms; or

R² and R³, together with the connecting carbon atom, represent anα-cycloalkanone ring system with 5 or 6 carbon atoms (for example anα-cyclopentanone or α-cyclohexanone ring system) which is optionallysubstituted by alkyl with up to 3 carbon atoms.

Surprisingly, the trifluoromethylimino-thiazolidine derivativesaccording to the invention have a more powerful fungicidal activity thanthe substances known from the state of the art. The compounds accordingto the invention thus represent an enrichment of the art.

The invention also provides a process for the production of atrifluoromethylimino-thiazolidine derivative of the formula (I) in whicha thioamide of the general formula (shown in the reactive enthiol form)##STR3## in which R¹, R² and R³ have the meanings stated above, isreacted with bis-trifluoromethylimino-oxalic acid difluoride, of theformula ##STR4## in the presence of a hydrogen fluoride-acceptor.

If (N-benzyl)-malonic acid thioamide methyl ester andbis-trifluoromethylimino-oxalic acid difluoride are used as startingmaterials, the course of the reaction can be represented by the equationwhich follows: ##STR5##

The thioamides of the formula (II), or (in cases in which R¹ representsan optionally substituted amino group) thiohydrazides, are knowncompounds and can be prepared by processes which are generally known.Thus, for example, malonic acid dithioamides are obtained by reactingmalonic acid amides with phosphorus pentasulphide (Ber. dtsch. chem.Ges. 39, B 298 (1906)) or by deacylating acetylacetone with 2 moles ofan isothiocyanate per mole of acetylacetone (J. prakt. Chem. 30, 63(1965), abstracted in Chem. Abstracts 64, 3411 d (1966), and LiebigsAnn. Chem. 695, 49 (1966)). Acetoacetic acid thioamides are obtained byreacting acetylacetone with, per mole, one mole of isothiocyanate (J.Am. Chem. Soc. 42, 1055 (1920) and Z. Chem. 16, 452 (1976)). Accordingto the same equation, acetoacetamides also react with aromaticisothiocyanates to give (N-aryl)-malonic acid thioamides (J. prakt.Chem. 34, 251 (1966)). (N-Aryl)-malonic acid thioamide esters canaccordingly also be prepared from acetoacetates and aromaticisothiocyanates (Z. Chem. 5, 104 (1965), abstracted in Chem. Abstracts63, 5546 d (1965), and Liebigs Ann. Chem. 695, 49 (1966)).(N-Alkyl)-malonic acid thioamide esters and thiohydrazide esters can beobtained in good yield in a simple manner by reacting the asymmetricdithiomalonic esters (Suomen Kemistilehti B 17, 28 (1944)) with primaryaliphatic amines or 1,1-disubstituted hydrazines (see Zh. Org. Khim. 11,1192 (1975)). Benzoylacetic acid thioamides orcycloalkan-2-one-thiocarboxylic acid anilides can be synthesized byacylation of α-morpholinostyrene or 1-morpholino-cycloalk-1-enes withisothiocyanates and subsequent acid hydrolysis (Chem. Ber. 95, 926(1926), abstracted in Chem. Abstracts 57, 4654 (1962)). Finally,cyanoacetic acid thioanilides are obtained by acylation of cyanoacetateswith aryl isothiocyanates and subsequent saponification anddecarboxylation of the adducts (Zh. Obsh. Khim. 32, 2248 (1962),abstracted in Chem. Abstracts 58, 7863 f (1963); Khim. Get. Soed. 1, 698(1965), abstracted in Chem. Abstracts 64, 9702 c (1966); and Khim. Get.Soed. 3, 713 (1967), abstracted in Chem. Abstracts 68, 49503 j (1968)).

Those secondary thioamides which have a mobile hydrogen atom in theα-position are advantageously used for carrying out the processaccording to the invention. The thioamides formally react in the enthiolform, such as has been shown in formula (II).

The bis-trifluoromethylimino-oxalic acid difluoride of the formula(III), also called perfluoro-2,5-diazahexa-2,4-diene, which is also usedas a starting material, is known (see J. Am. Chem. Soc. 89, 5007 (1967)or U.S. Pat. No. 3,660,511).

In the preparative process of the present invention, the customaryorganic solvents and diluents can be used as diluents, especiallyhydrocarbons, for example benzine, toluene and cyclohexane; nitriles,for example acetonitrile or propionitrile; chlorinated hydrocarbons,such as methylene chloride, chloroform and chlorobenzene; or ketones,for example acetone. The reaction is preferably carried out in acetoneor acetonitrile.

The customary acid-binding agents can be used as the hydrogen fluoridebinding agent. Alkali metal carbonates, alkali metal bicarbonates andtertiary amines, such as triethylamine, dimethylaniline or pyridine, canbe used as such agents. However, alkali metal fluorides, for examplesodium fluoride, are particularly preferably employed for bonding thehydrogen fluoride liberated.

The reaction temperatures can be varied within a substantial range. Ingeneral, the reaction is carried out at from -50° to +120° C.,preferably from -30° to +90° C.

For carrying out the process according to the invention, 1 mole ofbis-trifluoromethylimino-oxalic acid difluoride of the formula (III) ispreferably employed per mole of the compound of the formula (II). Thealkali metal fluoride, or another hydrogen fluoride-acceptor, isemployed in an approximately 2 to 4 molar amount. Amounts up to about20% less or more than the proportions indicated can be used withoutsubstantially lowering the yield. The bis-trifluoromethylimino-oxalicacid difluoride is appropriately added dropwise to a suspensionconsisting of the thioamide, the organic solvent and the hydrogenfluoride-acceptor, the mixture advantageously being initially cooledwith a cooling bath. After the reaction has ended (for example after aperiod of 30 minutes to 24 hours at room temperature) the hydrogenfluoride formed is filtered off, the filtrate is concentrated and thecrystalline residue is purified by recrystallization. However, after thereaction has ended, it is also possible to pour the resulting mixture,or the filtered solution, into ice-water and to filter off and ifappropriate recrystallize the residue obtained.

A variant of the process for the preparation of a compound according tothe invention consists in reacting a suitable thioamide withN,N'-bis-(trifluoromethyl)-tetrafluoroethylene-1,2-diamine, which isknown, in the presence of a hydrogen fluoride-acceptor in thetemperature range between -50° and +120° C.

In this case, 1 mole ofN,N'-bis-(trifluoromethyl)-tetrafluoroethylene-1,2-diamine and 4-5 molesof the hydrogen fluoride-acceptor are advantageously employed per moleof thioamide (this process variant is carried out analogously to themethod disclosed in DT-OS (German Published Specification ) No.2,210,882).

The active compounds according to the invention exhibit a powerfulfungitoxic action. They do not damage crop plants in the concentrationsrequired for combating fungi. For these reasons, they are suitable foruse as plant protection agents for combating fungi. Fungitoxic agentsare employed in plant protection for combating Plasmodiophoromycetes,Oomycetes, Chytridiomycetes, Zygomycetes, Ascomycetes, Basidiomycetesand Deuteromycetes.

The active compounds according to the invention have a broad spectrum ofaction and can be used against parasitic fungi which attack above-groundparts of plants or which attack the plants through the soil, as well asagainst seed-borne pathogens.

The compounds have a good activity against Fusicladium dendriticum, theapple scab causative organism, against Phytophthora infestans, thepotato blight and rot causative organism, and against Pyricularia oryzaethe causative organism of rice blast, and against Pellicularia sasakii,the causative organism of sheath blight of rice.

However, the compounds according to the invention are also activeagainst other fungi which attack rice plants or other cultivated plants,such as, for example, against Mycosphaerella musicola, Verticilliumalboatrum and Phialophora cinerescens, and against the bacteriumXanthomonas oryzae.

The active compounds can be converted into the customary formulations,such as solutions, emulsions, wettable powders, suspensions, powders,dusting agents, foams, pastes, soluble powders, granules, aerosols,suspension-emulsion concentrates, seed-treatment powders, natural andsynthetic materials impregnated with active compound, very fine capsulesin polymeric substances, coating compositions for use on seed, andformulations used with burning equipment, such as fumigating cartridges,fumigating cans and fumigating coils, as well as ULV cold mist and warmmist formulations.

These formulations may be produced in known manner, for example bymixing the active compounds with extenders, that is to say liquid orliquefied gaseous or solid diluents or carriers, optionally with the useof surface-active agents, that is to say emulsifying agents and/ordispersing agents and/or foam-forming agents. In the case of the use ofwater as an extender, organic solvents can, for example, also be used asauxiliary solvents.

As liquid solvents diluents or carriers, especially solvents, there aresuitable in the main, aromatic hydrocarbons, such as xylene, toluene oralkyl naphthalenes, chlorinated aromatic or chlorinated aliphatichydrocarbons, such as chlorobenzenes, chloroethylenes or methylenechloride, aliphatic or alicyclic hydrocarbons, such as cyclohexane orparaffins, for example mineral oil fractions, alcohols, such as butanolor glycol as well as their ethers and esters, ketones, such as acetone,methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, orstrongly polar solvents, such as dimethylformamide anddimethylsulphoxide, as well as water.

By liquefied gaseous diluents or carriers are meant liquids which wouldbe gaseous at normal temperature and under normal pressure, for exampleaerosol propellants, such as halogenated hydrocarbons as well as butane,propane, nitrogen and carbon dioxide.

As solid carriers there may be used ground natural minerals, such askaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite ordiatomaceous earth, and ground synthetic minerals, such ashighly-dispersed silicic acid, alumina and silicates. As solid carriersfor granules there may be used crushed and fractionated natural rockssuch as calcite, marble, pumice, sepiolite and dolomite, as well assynthetic granules of inorganic and organic meals, and granules oforganic material such as sawdust, coconut shells, corn cobs and tobaccostalks.

As emulsifying and/or foam-forming agents there may be used non-ionicand anionic emulsifiers, such as polyoxyethylene-fatty acid esters,polyoxyethylene-fatty alcohol ethers, for example alkylaryl polyglycolethers, alkyl sulphonates, alkyl sulphates, aryl sulphonates as well asalbumin hydrolysis products. Dispersing agents include, for example,lignin sulphite waste liquors and methylcellulose.

Adhesives such as carboxymethylcellulose and natural and syntheticpolymers in the form of powders, granules or latices, such as gumarabic, polyvinyl alcohol and polyvinyl acetate, can be used in theformulations.

It is possible to use colorants such as inorganic pigments, for exampleiron oxide, titanium oxide and Prussian Blue, and organic dyestuffs,such as alizarin dyestuffs, azo dyestuffs or metal phthalocyaninedyestuffs, and trace nutrients, such as salts of iron, manganese, boron,copper, cobalt, molybdenum and zinc.

The formulations in general contain from 0.1 to 95 l percent by weightof active compound, preferably from 0.5 to 90 percent by weight.

The active compounds can be used as such or in the form of theirformulations or the use forms prepared therefrom, such as ready-to-usesolutions, emulsifiable concentrates, emulsions, suspensions, wettablepowders, pastes, soluble powders, dusting agents and granules. They areused in the customary manner, for example by spraying, atomizing,misting, dusting, scattering, fumigating, gassing, watering, dressing orencrusting.

The concentrations of active compound in the ready-to-use formulationscan be varied within substantial ranges. They are, in general, from0.0001 to 10%, preferably from 0.01 to 1%.

The compounds according to the invention also have an acaricidal action.

The present invention also provides a fungicidal composition containingas active ingredient a compound of the present invention in admixturewith a solid or liquefied gaseous diluent or carrier or in admixturewith a liquid diluent or carrier containing a surface-active agent.

The present invention also provides a method of combating fungi whichcomprises applying to the fungi, or to a habitat thereof, a compound ofthe present invention alone or in the form of a composition containingas active ingredient a compound of the present invention in admixturewith a diluent or carrier.

The present invention further provides crops protected from damage byfungi by being grown in areas in which immediately prior to and/orduring the time of the growing a compound of the present invention wasapplied alone or in admixture with a diluent or carrier.

It will be seen that the usual methods of providing a harvested crop maybe improved by the present invention.

The preparation of the novel compounds is shown in the followingillustrative example:

EXAMPLE 1 (a) Preparation of the precursor

160 ml of acetylacetone, 400 ml of absolute ether and 23 g of finely cutsodium were stirred at room temperature for 2.5 hours. 135 g of phenylisothiocyanate were then added dropwise at room temperature and themixture was subsequently stirred at room temperature for 60 hours. 120ml of absolute methanol were then added dropwise and the mixture wasleft to stand at room temperature for 20 hours. It was taken up in 200ml of ice-water, to which 200 ml of 10% strength sodium hydroxidesolution had been added, the ether was separated off and the aqueoussolution was neutralized with 10% strength hydrochloric acid at about 0°C., while cooling. The precipitate was filtered off, washed with waterand dried and recrystallized from carbon tetrachloride. 157 g ofacetoacetic acid thioanilide of melting point 56°-58° C. were obtained.##STR6##

23 g (about 0.1 mol) of bis-trifluoromethylimino-oxalic acid difluoridewere added dropwise to a suspension of 19.3 g (0.1 mol) of acetoaceticacid thioanilide and 15 g (0.36 mol) of sodium fluoride in 120 ml ofacetone at about 5° to 15° C., while cooling with ice and stirring. Themixture was stirred at room temperature for 2 hours and the precipitatewas filtered off and rinsed with warm acetonitrile. The product phasewas then discharged onto ice and the solid was filtered off and rinsedwith a large amount of water, and the residue was recrystallized fromethyl alcohol. 32 g of2-acetyl-methylene-3-phenyl-4,5-bis-trifluoromethylimino-thiazolidine ofmelting point 189°-191° C. were obtained, that is to say 84% of theory.

The compounds which follow, of the general formula ##STR7## whereobtained in a corresponding manner:

    __________________________________________________________________________    Compound                              Melting                                 No.   R.sup.1   R.sup.2                                                                              R.sup.3        point (°C.)                      __________________________________________________________________________           ##STR8## H      COOCH.sub.3    165-167                                 3                                                                                    ##STR9## H      COOCH.sub.3    164-165                                 4                                                                                    ##STR10##                                                                              COOC.sub.2 H.sub.5                                                                   COOC.sub.2 H.sub.5                                                                           220-222                                 5                                                                                    ##STR11##                                                                              H                                                                                     ##STR12##     224-225                                 6                                                                                    ##STR13##                                                                              CN                                                                                    ##STR14##     286-287                                 7                                                                                    ##STR15##                                                                              CN     COOC.sub.2 H.sub.5                                                                           205-206                                 8                                                                                    ##STR16##                                                                              H                                                                                     ##STR17##     207                                     9                                                                                    ##STR18##                                                                              H      COOCH.sub.3    151-152                                 10                                                                                   ##STR19##                                                                              H      COOCH.sub.3    167-168                                 11                                                                                   ##STR20##                                                                              H                                                                                     ##STR21##     226-227                                 12                                                                                   ##STR22##                                                                              H                                                                                     ##STR23##     196-197                                 13                                                                                   ##STR24##                                                                              H                                                                                     ##STR25##     224-225                                 14                                                                                   ##STR26##                                                                              H                                                                                     ##STR27##     237-238                                 15                                                                                   ##STR28##                                                                              H      COOCH.sub.3    176-177                                 16                                                                                   ##STR29##                                                                              H      COOC.sub.2 H.sub.5                                                                           214-215                                 17                                                                                   ##STR30##                                                                              H      CN             218-219                                 18                                                                                   ##STR31##                                                                              H      COOC.sub.2 H.sub.5                                                                           193-194                                 19                                                                                   ##STR32##                                                                              H      COOC.sub.2 H.sub.5                                                                           167-168                                 20                                                                                   ##STR33##                                                                              H      COOCH.sub.3    136-137                                 21                                                                                   ##STR34##                                                                              H      COOC.sub.2 H.sub.5                                                                           166-167                                 22                                                                                   ##STR35##                                                                              H      COOC.sub.2 H.sub.4 OCH.sub.3                                                                 128-130                                 23                                                                                   ##STR36##                                                                              H      COOC.sub.2 H.sub.4 OCH.sub.3                                                                 146-147                                 24                                                                                   ##STR37##                                                                              H      COOCH.sub.3    227-228                                 25                                                                                   ##STR38##                                                                              H      COOCH.sub.3    217-218                                 26                                                                                   ##STR39##                                                                              H      COOC.sub.3 H.sub.7 -n                                                                        127-128                                 27                                                                                   ##STR40##                                                                              H      COOC.sub.3 H.sub.7 -n                                                                        137-138                                 28                                                                                   ##STR41##                                                                              H                                                                                     ##STR42##     203-204                                 29                                                                                   ##STR43##                                                                              H                                                                                     ##STR44##     187-188                                 30                                                                                   ##STR45##                                                                              H                                                                                     ##STR46##     200-202                                 31                                                                                   ##STR47##                                                                              H      COCH.sub.3     200-221                                 32                                                                                   ##STR48##                                                                              H      COCH.sub.3     202-203                                 33                                                                                   ##STR49##       CH.sub.2CH.sub.2CH.sub.2CH.sub. 2CO                                                          157-158                                 34                                                                                   ##STR50##       CH.sub.2CH.sub.2CH.sub.2CO                                                                   169-170                                 35                                                                                   ##STR51##       CH.sub.2CH.sub.2CH.sub.2CH.sub.2CO                                                           162-163                                 __________________________________________________________________________

The activity of the compounds of this invention is illustrated by thefollowing examples, wherein the compounds according to the presentinvention are each identified by the number (given in brackets) fromExample 1 hereinabove.

EXAMPLE 2

Agar plate test

Nutrient medium used:

20 parts by weight of agar-agar

200 parts by weight of potato decoction

5 parts by weight of malt

15 parts by weight of dextrose

5 parts by weight of peptone

2 parts by weight of disodium hydrogen phosphate

0.3 part by weight of calcium nitrate

Composition of the solvent mixture:

0.19 part by weight of acetone or dimethylformamide

0.01 part by weight of emulsifier (alkylaryl polyglycol ether)

1.80 parts by weight of water

Ratio of solvent mixture to nutrient medium:

2 parts by weight of solvent mixture

100 parts by weight of agar nutrient medium

The amount of active compound required for the desired active compoundconcentration in the nutrient medium was mixed with the stated amount ofsolvent mixture. The concentrate was thoroughly mixed, in the statedproportion, with the liquid nutrient medium (which had been cooled to 42deg.C.) and was then poured into Petri dishes of 9 cm diameter. Controlplates to which the preparation had not been added were also set up.

When the nutrient medium had cooled and solidified, the plates wereinoculated with the species of organisms stated hereinbelow andincubated at about 21 deg.C.

Evaluation was carried out after 4-10 days, dependent upon the speed ofgrowth of the organisms. When evaluation was carried out the radialgrowth of the organism on the treated nutrient media was compared withthe growth on the control nutrient medium.

The action against the species of fungi Colletotrichum coffeanum,Cochliobolus miyabeanus, Verticillium alboatrum, Pyricularia oryzae,Phialophora cinerescens, Mycosphaerella musicola and Pelliculariasasakii and against the bacterium Xanthomonas oryzae was tested.

Evaluation of the test showed that, for example, the following compoundsexhibited a superior action compared with the compounds mentioned in theprior art: compounds (2), (15), (17), (19), (20) and (33).

EXAMPLE 3

Pyricularia and Pellicularia test

Solvent: 11.75 parts by weight of acetone

Dispersing agent: 0.75 parts by weight of alkylaryl polyglycol ether

Water: 987.50 parts by weight

The amount of active compound required for the desired concentration ofactive compound in the spray liquid was mixed with the stated amount ofthe solvent and of the dispersing agent and the concentrate was dilutedwith the stated amount of water.

Rice plants about 2-4 weeks old were sprayed with the spray liquid untildripping wet. The plants remained in a greenhouse at temperatures of 22to 24 deg.C. and a relative atmospheric humidity of about 70% until theywere dry. Thereafter, the plants were inoculated with an aqueoussuspension of 100,000 to 200,000 spores/ml of Pyricularia oryzae andplaced in a chamber at 24 to 26 deg.C. and 100% relative atmospherichumidity.

Other rice plants, which had been sprayed and dried in theabove-described manner, were infected with a culture of Pelliculariasasakii grown on malt agar and were set up at 28 to 30 deg.C. and 100%relative atmospheric humidity.

5 to 8 days after the inoculation, the infection of all the leavespresent at the time of inoculation with Pyricularia oryzae wasdetermined as a percentage of the untreated but also inoculated controlplants.

In the case of the plants infected with Pellicularia sasakii, theinfection at the leaf sheaths after the same time was determined, againin relation to the untreated but infected control.

Evaluation of the tests showed that, for example, the followingcompounds exhibited a superior action compared with the compoundsmentioned in the prior art: compounds (2), (3), (1), (15), (17), (19),(20), (33) and (35).

EXAMPLE 4

Phytophthora test (tomato)/protective

Solvent: 4.7 parts by weight of acetone

Emulsifier: 0.3 part by weight of alkylaryl polyglycol ether

Water: 95 parts by weight

The amount of the active compound required for the desired concentrationof the active compound in the spray liquid was mixed with the statedamount of solvent and the concentrate was diluted with the stated amountof water which contained the stated additions.

Young tomato plants with 2 to 4 foliage leaves were sprayed with thespray liquid until dripping wet. The plants remained in a greenhouse for24 hours at 20 deg.C. and at a relative atmospheric humidity of 70%. Thetomato plants were then inoculated with an aqueous spore suspension ofPhytophthora infestans. The plants were brought into a moist chamberwith an atmospheric humidity of 100% and a temperature of 18-20 deg.C.

After 5 days the infection of the tomato plants was determined.

Evaluation of the test showed that, for example, the following compoundsexhibited a superior action compared with the compounds mentioned in theprior art: compounds (1), (9), (34) and (24).

EXAMPLE 5

Fusicladium test (apple)/protective

Solvent: 4.7 parts by weight of acetone

Emulsifier: 0.3 part by weight of alkylaryl polyglycol ether

Water: 95 parts by weight

The amount of active compound required for the desired concentration ofthe active compound in the spray liquid was mixed with the stated amountof solvent, and the concentrate was diluted with the stated amount ofwater which contained the stated amount of emulsifier.

Young apple seedlings in the 4-6 leaf stage were sprayed with the sprayliquid until dripping wet. The plants remained in a greenhouse for 24hours at 20 degrees C. and at a relative atmospheric humidity of 70%.They were then inoculated with an aqueous conidium suspension of theapple scab causative organism (Fusicladium dendriticum) and incubatedfor 18 hours in a humidity chamber at 18-20 degrees C. and at a relativeatmospheric humidity of 100%.

The plants were then brought into a greenhouse again for 14 days.

15 days after inoculation, the infection of the seedlings wasdetermined.

Evaluation of the test showed that, for example, the following compoundsexhibited a superior action compared with the prior art: compounds (1),(9), (10), (15), (33), (34) and (24).

EXAMPLE 6

Shoot treatment test/cereal rust

(leaf-destructive mycosis)/protective

To produce a suitable preparation of active compound, 0.25 part byweight of active compound was taken up in 25 parts by weight ofdimethylformamide and 0.06 part by weight of alkylaryl polyglycol etherand then 975 parts by weight of water are added. The concentrate wasdiluted with water to the desired final concentration of the sprayliquor.

To test the protective activity, one-leaved young wheat plants of theMichigan Amber variety were inoculated with a uredospore suspension ofPuccinia recondita in 0.1% strength aqueous agar. After the sporesuspension had dried on, the wheat plants were sprayed with thepreparation of active compound until dew-moist and were placed, forincubation, in a greenhouse for 24 hours at about 20 deg.C. and 100%relative atmospheric humidity.

After 10 days' dwell time of the plants at a temperature of 20 deg.C.and 80-90% atmospheric humidity, the occurrence of rust pustules on theplant was evaluated. The degree of infection was expressed as apercentage of the infection of the untreated control plants. The moreactive the compound, the lower was the degree of rust infection.

Evaluation of the test showed that, for example, the following compoundsexhibited a superior action compared with the prior art: compounds (2),(3), (1), (9), (10), (15), (16), (17), (18), (19), (20), (33), (22),(34), (24), (25), (26) and (35).

EXAMPLE 7

Shoot treatment test/powdery mildew of cereals

(leaf-destructive mycosis)/protective

To produce a suitable preparation of active compound, 0.25 part byweight of active compound was taken up in 25 parts by weight ofdimethylformamide and 0.06 part by weight of alkylaryl polyglycol ether;975 parts by weight of water were then added. The concentrate wasdiluted with water to the desired final concentration of the sprayliquor.

To test for protective activity, single-leaved young barley plants ofthe Amsel variety were sprayed with the preparation of active compounduntil dew-moist. After drying, the barley plants were dusted with sporesof Erysiphe graminis var. hordei.

After 6 days' dwell time of the plants at a temperature of 21-22 deg.C.and 80-90% atmospheric humidity the occurrence of mildew pustules on theplants was evaluated. The degree of infection was expressed as apercentage of the infection of the untreated control plants. The moreactive the compound, the lower was the degree of mildew infection.

Evaluation of the test showed that, for example, compound (34) exhibiteda superior action compared with the compounds mentioned in the priorart.

EXAMPLE 8

Seed dressing test/bunt of wheat

(seed-borne mycosis)

To produce a suitable dry dressing, the active compound was extendedwith a mixture of equal parts by weight of talc and kieselguhr to give afinely powdered mixture with the desired concentration of the activecompound.

Wheat seed was contaminated with 5 g of the chlamydospores of Tilletiacaries per kg of seed. To apply the dressing, the seed was shaken withthe dressing in a closed glass flask. The seed, on moist loam under acover of a layer of muslin and 2 cm of moderately moist compost soil,was exposed to optimum germination conditions for the spores for 10 daysat 10 deg. C. in a refrigerator.

The germination of the spores on the wheat grains, each of which wascontaminated with about 100,000 spore, was subsequently determinedmicroscopically. The smaller the number of spores which had germinated,the more effective was the active compound.

Evaluation of the test showed that, for example, the following compoundsexhibited a superior action, compared with the compounds mentioned inthe prior art: compounds (1), (17) and (22).

It will be appreciated that the instant specification and examples areset forth by way of illustration and not limitation, and that variousmodifications and changes may be made without departing from the spiritand scope of the present invention.

What is claimed is:
 1. A compound of the formula ##STR52## in which R¹represents an alkyl, alkenyl or alkynyl radical with up to 6 carbonatoms, which radical can be substituted by cyano or an alkoxy oralkylmercapto group with in either case up to 3 carbon atoms, orrepresents cycloalkyl with 5 to 6 carbon atoms, which is optionallysubstituted by alkyl with 1 to 3 carbon atoms, or represents aryl withup to 10 carbon atoms or aralkyl with up to 10 carbon atoms in the arylpart and 1 or 2 carbon atoms in the alkyl part, the aryl radicalsmentioned being optionally substituted by halogen, cyano, nitro oralkyl, alkoxy or alkylmercapto with in each case up to 3 carbon atoms,or represents an amino group --NR⁴ R⁵, whereinR⁴ and R⁵ eachindependently represents alkyl with 1 to 12 carbon atoms or, togetherwith the connecting nitrogen atom and optionally one or more furtherhetero-atoms selected from oxygen, sulphur and nitrogen, form aheterocyclic ring with 5 to 7 ring atoms, R² represents hydrogen, cyanoor an acyl group with a total of up to 10 carbon atoms, and R³represents cyano, or represents an acyl group with a total of up to 10carbon atoms, alkylsulphonyl with up to 6 carbon atoms or arylsulphonylwith up to 10 carbon atoms in the aryl part, which aryl part isoptionally substituted by alkyl with up to 3 carbon atoms and/or nitroand/or halogen, or represents an amide or thioamide group comprising theradical CO--NR⁶ R⁷ or CS--NR⁶ R⁷, in which R⁶ represents hydrogen oralkyl with up to 4 carbon atoms, and R⁷ represents alkyl with up to 6carbon atoms, cycloalkyl with 5 or 6 carbon atoms or phenyl, whichphenyl can be substituted by halogen, nitro or alkyl, alkoxy oralkylmercapto with in each case up to 4 carbon atoms, or R² and R³,together with the connecting carbon atom, represent an α-cycloalkanonering system with 5 or 6 carbon atoms which is optionally substituted byalkyl with up to 3 carbon atoms.
 2. A compound according to claim 1,wherein such compound is2-acetyl-methylene-3-phenyl-4,5-bis-trifluoromethylimino-thiazolidine ofthe formula ##STR53##
 3. A compound according to claim 1, wherein suchcompound is2-α-ketocyclopentylidene-3-phenyl-4,5-bis-trifluoro-methylimino-thiazolidineof the formula ##STR54##
 4. A compound according to claim 1, whereinsuch compound is2-α-ketocyclohexylidene-3-o-tolyl-4,5-bis-trifluoro-methylimino-thiazolidineof the formula ##STR55##
 5. A fungicidal composition containing asactive ingredient a fungicidally effective amount of a compoundaccording to claim 1 in admixture with a diluent.
 6. A method ofcombating fungi which comprises applying to the fungi, or to a habitatthereof, a fungicidally effective amount of a compound according toclaim
 1. 7. The method according to claim 6, in which said compoundis2-acetyl-methylene-3-phenyl-4,5-bis-trifluoromethylimino-thiazolidine,2-α-ketocyclopentylidene-3-phenyl-4,5-bis-trifluoro-methylimino-thiazolidine,or2-α-ketocyclohexylidene-3-o-tolyl-4,5-bis-trifluoro-methylimino-thiazolidine.